1. Field of the Invention
The present invention relates to an Internet Protocol (IP) based voice/video communication system and a call pickup/forwarding method. More particularly, the present invention relates to an IP based voice/video communication system and a call pickup/forwarding method by which a voice/video incoming call received in a first terminal can be picked up by a second terminal and/or a call forwarding mode of the incoming call can be set to automatically forward an incoming call received in the first terminal to second terminal. In addition, the present invention also relates to a program storage device, readable by a machine, tangibly embodying a program of instructions executable by the machine to perform the call pickup/forwarding method.
2. Description of the Related Art
In general, Internet-phone services are used to provide voice communication by using a worldwide communication infrastructure, that is, the Internet instead of a conventional Public Switched Telephone Network (PSTN). The conventional PSTN as a circuit switching network performs static switching while providing a fixed bandwidth of 64 Kbps to guarantee communication quality. However, the Internet, as a packet switching network, performs dynamic routing to provide best-effort services, thereby rarely guaranteeing communication quality. Nevertheless, Internet phones are getting more widely used since they can provide inexpensive long distance calls as well as create various forms of services.
The Internet-phone services can be classified into PC-to-PC, PC-to-Phone, Phone-to-PC and Phone-to-Phone services. In the PC-to-PC service, two users who want to communicate with each other use their multimedia computers as Internet-phone terminals. The computers can be connected to each other on a Local Area Network (LAN), or connected to telephone lines via modems to use the Internet via an Internet Service Provider (ISP). A voice signal is sampled, compressed and packeted in a codec with software of a transmitting PC, and a received voice signal is regenerated by a sound card in a receiving PC.
In the PC-to-Phone service, a PC is first connected to an Internet-phone gateway and then a telephone number of a counterpart to call is inputted to the gateway so that the gateway interprets it to connect the PC to a counterpart telephone via a conventional PSTN.
In the Phone-to-PC service, a subscriber of a conventional PSTN connects to an Internet-phone gateway and provides the information of a counterpart to call so that the Internet-phone gateway allows the subscriber to communicate with a corresponding PC via the Internet.
The Phone-to-Phone service allows communication between conventional telephones via the Internet. In the Phone-to-Phone service, a user connects to a nearby gateway using a public telephone connected to a PSTN, and then inputs a counterpart telephone number after user authentication and caller identification for charge. Then, a calling gateway packets the counterpart telephone number and sends it to a gateway nearest to a receiving part. The receiving part gateway converts the packet into the telephone number again to call the counterpart via the PSTN. Upon establishment of the connection setup between the two users, voice data is coded in a gateway and transmitted via the Internet, and a counterpart gateway decodes the coded voice data into a voice signal that is sent to the counterpart via the PSTN.
Further, the IP-based voice/video telephone is being developing in various forms in both the office and home automation environment. In particular, the recent office and home environment mainly utilizes a private system using an Access Point (AP) such as a wireless LAN communication arrangement, which allows voice/video communication to be performed via a personal terminal, (for example, a PDA, a digital TV and a home pad).
However, because the voice/video communication can be performed only between a calling terminal and a receiving terminal, there is a problem in that mobility is not guaranteed but rather depends upon the position of the receiving terminal, in particular, when the receiving terminal is located in a home.
For example, if a call signal is received in a terminal in a bedroom when a subscriber is working in a living room, the subscriber must go to the bedroom to answer the call with a corresponding voice/video terminal (for example, a TV). When the subscriber wants to perform communication via a home pad on a refrigerator in the kitchen instead of the TV during communication, because call forwarding is not enabled, the subscriber must continue conversation via the TV or asks a caller to call again to the refrigerator home pad. This can be an annoyance or inconvenience to the user.
Furthermore, because the subscriber cannot pick up a incoming call with a terminal at hand to answer the call if the call is received by a remotely located terminal, there is a problem in that the mobility of the subscriber is not guaranteed.
The following patents each discloses features in common with the present invention but do not teach or suggest the inventive features specifically recited in the present application: U.S. Patent Application No. 2004/0028205 to Lim et al., entitled METHOD FOR PERFORMING EXTERNAL CALL FORWARDING BETWEEN INTERNET AND TELEPHONE NETWORK IN WEB-PHONE SYSTEM, published on Feb. 12, 2004; U.S. Patent Application No. 2003/0108176 to Kung et al., entitled PERSONAL IP FOLLOW-ME SERVICE, published on Jun. 12, 2003; U.S. Patent Application No. 2003/0210776 to Sollee et al., entitled METHOD AND APPARATUS FOR PROVIDING ADVANCED IP TELEPHONY SERVICES IN AN INTELLIGENT ENDPOINT, published on Nov. 13, 2003; U.S. Patent Application No. 2004/0008621 to Yaker, entitled SYSTEM AND METHOD FOR PROVIDING ADVANCED CALLING FEATURES TO A PACKET NETWORK-BASED COMMUNICATION DEVICE AND PACKET NETWORK EMPLOYING THE SAME, published on Jan. 15, 2004; U.S. Patent Application No. 2004/0017803 to Lim et al., entitled CALL FORWARDING METHOD, published on Jan. 29, 2004; U.S. Patent Application No. 2004/0028205 to Lim et al., entitled METHOD FOR PERFORMING EXTERNAL CALL FORWARDING BETWEEN INTERNET AND TELEPHONE NETWORK IN WEB-PHONE SYSTEM, published on Feb. 12, 2004; U.S. Patent Application No. 2004/0037272 to Park, entitled METHOD OF FORWARDING PACKET CALLS IN MOBILE COMMUNICATION SYSTEM, published on Feb. 26, 2004; U.S. Patent Application No. 2004/0042607 to Gallant et al., entitled METHOD OF AND SYSTEM FOR PROVIDING INTELLIGENT NETWORK CONTROL SERVICES IN IP TELEPHONY, published on Mar. 4, 2004; and U.S. Patent Application No. 2004/0076140 to Begeja et al., entitled METHOD AND SYSTEM FOR REMOTE CALL FORWARDING OF TELEPHONE CALLS FROM AN IP CONNECTION, published on Apr. 22, 2004.